Carbureter



N. LOMBARD.

CARBURETER. A PPLICATION FILED AUG- 27. 19W.

Patented Au 9, 1921.

for u UNITED- STATES PATEN T ,OFFICE- I NATHANIEL LoMBAImorwoncns'rnn,MASSACHUSETTS, assrenon 'ro LOMBARD OARBURETOR'COMPANY, or woncasmn,MASSACHUSETTS, A CORPORATION 01:

MASSAC HUSETTS.

CARBURETER.

To all whom it may concern: b

Be it known that I, NATHANIEL LOMBARD, a citizen of the United Statesresiding at Worcester, in the county of orcester and CommonwealthofMassachusetts have invented a new and useful Improvement inCarbureters, of which the following, taken in connection with theaccompanying drawings, is .aspecification. v The present inventionrelates to carbureters, for use with internal combustion engines and thelike, to form an explosive mixture of air andgaseous fuel, such asgasolene or kerosene.

The object of my present invention is toprovide acarbureterj'of extremesimplicity of structure, with a minimum. of operating parts due to theelimination of the usual float control of the liquid fuel, the air valvemechanism, and the throttle or butterfly. valve between the'carbureterand engine.

Further objects are, toprovide for a more intimate mixture of the liquidfuel and air; to control the proper proportions of air and .liquid fuelby means of a single manually movable part; to momentarily increase therichness of the mixture in starting the englne or producing a suddenincrease 1n the speed of the engine, and to make the suction of theengine available under varying conditions of operation; to maintain asupply of liquid fuel without utilizing the force of gravity, therebyobviating the-necessity of intermediate fuel reservoirs between thecarbureter and a source of fuel supply.

These objects, among others, I accomplish by the construction andarrangement of parts as hereinafter described, the features ofnoveltybeing pointed out in the appended claims, reference being had to the accom panyingx, rawing, in which Figure 1 IS a vertical sectional view ofmy improved form of carbureter, with portionsv of the shell broken awayto disclose the interior construction more clearly. Fig. 2 is a detailview illustrating a part of the carbureter.

As herein shown, my improved carburetor is inclosed by a. two partshell, the upper part 1 of said shell'being joined in any suitable wayat 2 to the lower part 3, whereby to constitute a singlecontinuous'inclosure. Said inclosure communicates with the enginemanifold by an integral extension 4 near the top of shell portion 1, asis usual in devices of this class. Below the extension 4 theSpecification of Letters Patent. Patented Aug. 9, 1921- Applicatioafiled August 27, 1917. Serial No. 188,264.

shell portion 1 provides an annular valve seat 5, for cooperation withafrusto-conical valve member'6 to controlthe flow of airwhich is admittedfor mixture withthe li u1d fuel, as hereinafter described. The she I orcasing opposite the spindle'21 is provided with a sight glass l toprovide means for the inspection of the mixin chamber.

The valve 6 is carrie on a stem 7, which is vertically slidable in anelongated bearing 8 thatprojects upwardly from a bottom closure 9 forthe lower shell portion 3. The

valve 6 is raised or lowered with respect to its seat 5 by means of arack 10 on-steni 7, I

which is in mesh with a segmental gear 11 on rock shaft 12. The shaft 12is journaled in a suitable bearing 13 projecting inwardly from the sidewall of shell portion 1, and said shaft is operated by a lever arm 14which may be connected in any desired manner to the usual hand or footthrottle device, as commonly employeddn the usual fprm of carbureter toactuate the butterfly or mixture valve of the engine. In the positionshown, the valve 6 is effective to shut oifpthe flow of air past itsseat 5; as said valve is lowered, by movement of lever arm 14. a.

constantly increasing volume of air will be .drawnpast said seat, due tothe frusto-con- 7, as above described. The passage 15 is contracted atits upper end, near the top of valve 6, to form an annular valve seat19,

opening through the center of valve 6, and

expanding downwardly as at 20, to the size of passage 15. The seat 19006 erat'es with a downwardly tapering normal y stationary member 21,which )rojects therethrough into the passage 15. he up er end of member21 is substantially cylin ri'cal and of a size to close the valve seat19; from said upper end, the member 21 gradually tapers down wardly andmerges finally into a cylindrical section of smaller diameter 22. Aswill'be apparent, the raising and lowering of valve G will control thesize of the restricted annular nozzle which is thus formed between seat19 and member 21, and thus the liquid fuel which passes through saidnozzle and is thereby broken up into a finely divided mist or spray willvary in volume proportionately to the volume of air passing the valveseat 5. Such variation is due to the downward taper of member 21, andthe maximum volume of liquid fuel will flow past the valve seat 19 whenthe reduced cylindrical section 22 is opposite said valve seat; at thistime the maximum volume of air will obviously pass the seat 5.

' All the air for admixture with the liquid fuel above the valve seat 19is admitted through an opening 23 in-the side wall of lower shellportion 3. Said shell portion 3 provides an annular seat 21 forcotiperation with an annular shoulder 25 on a jvalve member 26, whichsurrounds and is'guided by the bearing 8. The valve member 26 has acylindrical weighted extension 27 which has a snug sliding fit in acylindrical bore 28 at the lower end of shell portion 3. Said valvemember 26 is preferably reduced in section near the middle, forming awaist 26 connecting the inverted conical part 26 with the cylindricalpart 27, to afford an ample air space 29 within the shell portion 3 andbelow the valve seat24, so the atmospheric pressure against the underside of the valve 26 will lift the valve 26 when the operation of theeng ne produces a vacuum in the vacuum chamber between the valve seats 5and 24.

lVith the valve member 26 in full line position herein shown, the flowof any air past the seat 24 is prevented, due to the contact of shoulder25 with said seat. However, the slightest raising of valve member 26permits the passage of an appreciable volume of air, since said member.just below the shoulder 25 is smaller in diameter than the valve seat24, and gradually tapers downwardly as at 30. Therefore as the valvemember 26 is gradually raised, an increasing volume of air is renderedavailable for admixture with the liquid fuel, and the rush of said airthrough the seat 24 is effective to assist in maintaining the valvemember 26 in raised position, due to the outward taper 31 of said valvemember above the shoulder 25. In the maximum open position of said valvemember 26, as indicated herein by the broken lines 26, the rush of airthrough the seat 24 is effective against the downwardly tapering portion32 thereof, to assist in sustaining said member in its raised position,against the force of gravity tending to lower and close the same.

The operation of my thus far described is as tapers of air valve 6 andthe liquid fuel controlling member 21 may be so proportioned,

improved device as running slowly, or

follows :-The

that, in normal operation, the relative amounts of air and fuel in themixture which is formed above valve 6 will be substantially constant, inall positions of said valve, between the full open position and theentirely closed, position. The liquid fuel is subjected to the fullsuction of the engine cylinders. and likewise, this suction, as soon asthe valve 6 is lowered, is available to lift the valve member 26. andthus to inaugurate the flow of air for admixture with said liquid fuel.However. on account of the inertia of the member 26, and also the(lashpot action of its extension 27 within the bore 28, an appreciableinterval of time will elapse before said member responds fully by its upand down motion to the suction thereon, and assumes a heightcommensurate with the degree of said suction. In other words, in normaloperation, the member 26' will be sustained by the suction and by therush of air through seat 24, at a height which 'aries with the above twoforces,-but invariably this height is not reached for an appreciabletime after the suction to ultimately produce the same has becomeavailable, and an appreciable time will also elapse, when the suction isdecreased, before the valve member 26 will assume the full line positionas represented in the drawing. f

The above described action is extremely useful when the engine is beingstarted up,

as will be seen, since a very rich mititur is automatically produced,owing to the i i,- tial suction being exerted almost entirely on theliquld fuel nozzle 'and notwithstanding the fact that the air valve 6may be Wide Furthermore, when the engine is idling, on a throttledexplosive charge, a sudden lowering of valve 6, to cause the engine topick up quickly,

open.

. will be respondedto by an extremely grad ual elevation of the member26 from its former relatively low level of flotation. Thus a richermixture is automatically produced in this contingency, which preventsknocking and strain on the engine while it is being accelerated.

In normal continued operation, both air and fuel are subjected to thesuction from the engine cylinders, to the same degree, and the formationof the mixture being thus dependent upon this suction, it is clear thatno butterfly or mixture valve in the extension 4, or in the'enginemanifold, is necessary, since thevalve 6 and member 21 perform all thefunctions ofsuch a butterfly valve in controlling the amount of mixturepassing to the engine. Moreover, a distinct advantage is gained by theelimination of this butterfly valve, since'the latter, when in partlyclosed or throttled position in the ordinary carbureter, reduces thedegree of suction actmg on the fuel; in the present llt) ' give,temporarily, a rich mixture or start-- relatively large construction,however, the full suction of all the cylinders is constantly exerted todraw the fuel in passa e 15 at a-high 'velocity through the variab areadily aerated mist or spray. v

r The member 21 is carried on a screw 33 of pable of limited movement inits bearing, so as to vary and adjust the position of member 21. To thisend the screw 33has attached thereto, outside of shell portion 1, alever 34which may be connected, if desired,to the usual mixtureregulating lever,

not shown, which is commonly em loyed to ingpurpos'es. The actuation oflever 34, as

" will be'seen, varies the normally-fixed position ofmember'21, by meansof screw 33, so that, the valve 6 being considered as stationaryatanygiven moment, the quantity of gaseous fuel entering the combustiblemixture may be varied by such manipulation,

the quantity of air remaining constant. To

provide for a further adjustment, such as might be necessary owing toextreme temperature changes, the lever 34 may be dis,- oonnected byloosening screw 35, to allow the movement of screw 33 by its head 36,and thereafter the screw'35 may be tightened to secure the partstogether in the new position of adjustment.

To provide for a constant supply of air impinging directly on the fuelspray where .the mixture is formed, I prefer to form a series of airducts 37 through the bodyo-f valve'6, which are at all times subject tothe suction from the cylinders. The air ducts37 converge toward theirdelivery ends to cause the air currents passing therethrough to 1mpinge'against the current of liquid fuel de-' livered from the valve 6.- Theoperation of my improved carbureter is sufficiently clear from theforegoing detailed description, it

. being obvious that various changes and modifications may be introducedwithout H departing from the spirit of the invention as defined in theannexed claims. 1

'- In the operation of my improved carbureter, the space inclosed in theextension 4:

' constitutes a mixing chamber in which the thorough mixture of the airand liquid fuel is promoted by the cross currentsv of air passingthrough the converglng passages 37 and directed against the current ofliquid fuel. The space inclosed in the casing 1 be tween the valve seats5 and 24 I term the vacuum chamber, as the vacuum produced therein bythe suction of the engine controls the movement of the air valve 26. Thespace inolosed in the case 3, surrounding the waist 'of the air valve 26I termthe air pressure chamber as it subjects the air valve 26 tothemnormal atmospheric pressure through le nozzle, thus pro motin-g theaction of said nozzle in forming itch which isthreaded' through the top0 shell portion 1 and is ca- 'chambers, a valve the opening 221- Thelower cylindrical part of the casing 3-fitting the cylindrical base ofthe air valve 26 constitutes a dashpot to restrain the movement of theair valve 26.

Iclaim, f r I. In the carbureter of an .internal combusclosing threeseparate chambers, namely, mixing, vacuum and air chambers located oneabove the other in the order named with the Inixingchamber uppermost,with valve controlled openings between each of said chambers, saidairchamber having a com-- munication with the outside air, a valve ;for

closing the opening between the mixing and,

vacuum chambers, provided with a hollow valve stem extending throughtion'engine, the combination ofa casing invacuum and air chamberslocated tween the mixing and vacuum chambers,

provided with a hollow valve stem extendhaving a connection at its lowerend with a source of fuel supply, said hollow valve stem having acontracted opening at its upper end leading to the mixing chamber, adownwardly tapered pin extending through the mixing chamber and saidcontracted opening, and means for manually imparting a longitudinalmovementto. said valve stem, whereby the movement of said valve and theadmission of fuel to the migring chamber is simultaneously controlled atwill.

'3. In the carbureter of an internal combustion engine, the combinationof a casing.

inclosing three separate chambers, namely, mixing, vacuum and airchambers located the mixing chamber uppermost, with valve controlledopenings between each of said chambers, .a valve for closingthe openingcarried upon the upper end of a hollow valve stem, a valve stemextending through the bottom of the casing and having a conneci tion atits lower end with a source of fuel supply, said valve stem having-acontracted opening at itslupper end and said valve having a series ofpassages therethrough converging toward the top of the valve, wherebyair currents passingvthrough said converging openings will impingeagainst the current of fuel passing through the contracted. opening ofthe valve stem.

4. In thecarburetcr of an internal combustion engine, the combinationwith a ing through the bottom of the casingand one above the other intheorder named, with p A between the mixing and vacuum chambers,

casing inclosing three separate chambers, namely, mixing. acuum and airchambers located one above the other in the order named, with the mixingchamber uppermost, with valve controlled opening-s between each of saidchambers, of a valve for closin; the opening between the mixing andvacuum chambers provided with a hollow valve stem opening into themixing chamber and extending through the bottom of the casing and havinga connection outside the casing with a source of fuel supply, anelongated bearing extending upwardly from the bottom of the casing forsaid valve stem, and means for manually moving said valve stem in saidelongated bearing at will.

5. In the carbureter of an internal combustion engine, the combinationwith a casing inclosing three separate chambers,

namely, mixing, vacuum and air chambers located one above the other inthe order named. with the mixing chamber uppermost and havin valveqcontrolled openings between each of said 'chambers, of a valve forcontrolling the opening between the mixing and the vacuum chambers,means for manually opening said valve to subject the vacuum chamber tothe suction produced by the operation of the engine, means for supplyingfuel through said valve to the mix ing chamber, and ai'avity-valveclosing the opening between 1110 vacuum and air chambers" iDated this 23rd day of August, 1917.

NATHANIEL LOMBARD. Witnesses: 5

NELLIE \VHALEN, (h-1o. H. KENNEDY, Jr.

